Methodology For appraisal Of Natural Hazard Vulnerability In Us Using Remote Sensing

Introduction

Coastal zone is defined as "the coastal waters (including the lands therein and thereunder) and the adjacent shorelands (including the waters therein and thereunder), strongly influenced by each other and in proximity to the shorelines of the several coastal states, and includes islands, transitional and intertidal areas, salt marshes, wetlands, and beaches." Coastal locations were some of the first settled in the country, and have always accounted for a major ration of the unabridged population. They were the former centers for transportation, tourism, recreation, market fishing, and other industry. This coastal zone remains a crucial segment of the nation's unabridged economy. A collection of natural hazards regularly threaten this coastal zone. Severe meteorological events such as hurricanes, tropical cyclones, and nor'easters are particularly harsh on coastal areas, often resulting in damages from high winds, storm surge, flooding, and coast erosion. Tsunamis, whose destructive force is characterized by potentially devastating flood inundation, are uniquely coastal events resulting from offshore earthquakes, landslides, or volcanic activity. Coastal locations are also subjected to the impacts of long-term hazards such as lasting coastal erosion, potential sea-level rise, and global atmosphere change.

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Coastal hazard events can significantly work on or even alter the natural environment. Their impacts are ordinarily not determined to be "disastrous" unless they involve damages to human populations and infrastructure. When citizen and asset are not present, hazards are merely natural processes that alter the environment. When citizen and asset is present then the impacts of hazards are viewed quite differently. The former focus is no longer on the natural processes related with a major hazard event, but instead on the disastrous results that can be measured by lives lost, asset damages, and economic and environmental impacts.

The impacts of natural hazards are becoming increasingly costly and devastating. Hazard impacts on the natural environment become more devastating because human improvement has altered the potential of natural systems to recover from such events. Experts believe that the statistics on disaster losses continue to rise worldwide due to a aggregate of factors that include a rise in the whole of hazard events due to global atmosphere change or natural cyclical trends, and an growth in human exposure in perilous locations.

Some of the decrease in disaster damages worldwide could also be the effect of improvements in disaster monitoring and reporting capabilities, particularly in developing countries. But disaster loss increases in the United States seem to be most closely tied to increased human exposure in high risk areas such as the nation's coasts.

The United States has an great and diverse coastline that supports a disproportionate ration of the nation's population. The nation's 451 coastal counties include just over 50 percent of the U.S. Population, yet only inventory for about 20 percent of the total U.S. Land area. while the last decade, 17 of the 20 fastest growing counties were settled along the coast. In addition, 19 of the 20 most densely populated counties in the nation are coastal counties. These coastal counties possess economic gain through natural resources, marine trade and commerce. These coastal counties also possess economic loss due to the natural hazards, overexploitation and exponential citizen growth. An estimate of both the economic gain and economic loss is briefly discussed as follows.

Economic gain in U.S. Coastal zone

Nature narrative (May 1997), a group of ecologists estimated the value on ecosystem in the coastal zone. They estimated that the worth of the services for marine ecosystems is almost trillion per year. agreeing to Sea Technology magazine, the value of goods and services sold by the ocean/marine industry was estimated in 1995 as billion annually. Offshore oil and gas production has become very important and the 1996 value was more than billion and the every year offshore production is increasing. agreeing to the National Oceanic and Atmospheric management (Noaa), 77 million pounds (meat weight) of shellfish were harvested from U.S. Coastal waters in 1995, with a dockside value of 0 million.

Current Noaa estimates with regard to the recreational uses of U.S. Coastal areas includes: almost 94 million citizen boat and fish annually; the average American spends 10 recreational days on the coast each year; The coasts (excluding the Great Lakes coastline) withhold 25,500 recreational facilities; More than 180 million Americans visited ocean and bay beaches in 1993; Recreational fishing contributes .5 billion annually to the U.S.
economy; Coastal recreation and tourism create to billion annually.

Economic loss in U.S. Coastal zone

Disaster losses in the United States coastal zone are currently estimated conservatively at billion annually. The disaster loss between 1975 and 1994 is estimated as 0 billion. 80 percent of the losses were imposed by meteorological events and 10 percent were the effect of earthquakes and volcanoes. A great earthquake (magnitude 8 or larger) has not struck a major metropolitan area since the 1906 San Francisco earthquake. An ultimate or catastrophic hurricane (Class 4 or 5) has not directly struck a major urban area since the one that hit Miami, Florida, in 1926. Yet even without such disasters, which might create losses well over 0 billion, the unabridged costs of natural hazards, such as ultimate weather, drought, and wildfires, are estimated at billion per year for the past 5 years, or almost billion per week. In the United States, the direct costs to heal the damage average about billion per year, of which over billion is due to tornadoes, hurricanes, floods and earthquakes.

The Fema coastal erosion study conducted by The Heinz town for Science, Economics and the Environment estimates that almost 25 percent of homes and other structures within 500 feet of the U.S. Coastline and the shorelines of the Great Lakes will fall victim to the effects of erosion within the next 60 years. Especially hard hit will be areas along the Atlantic and Gulf of Mexico coastlines, which are startling to inventory for 60 percent of nationwide losses. The narrative estimates that costs to U.S. Homeowners will average more than a half billion dollars per year, and that further improvement in high erosion areas will lead to higher losses. Thirty-four floods have been reported in Wake County (data source: Ndcd and Sheldus). The total coastline of mapped coast of Gulf of Mexico coast is about 8058 km out of which 3387 kms is in very high risk, 1056 kms is in high risk, 2968 km is in gently risk and 547 kms is in low risk kind due to sea level rise. So the 42 % of the coast line is in high risk, 37 % moderate risk and 8 % low risk (Robert Thieler et.al. 2001).

Hurricane Mitch, one of the most remarkable and damaging storms experienced in Central America, struck between 26 October and 1 November 1998. A kind V hurricane, the event was characterized by laberious rainfall and high winds, dumping a year's worth of precipitation in less than one week on the region, causing the overflow of rivers, floods, mudslides and landslides. Thousands of citizen were killed and left homeless. Mitch caused billions of dollars of damage, and left huge tasks of reconstruction, resulting in the loss of decades of improvement efforts in the region.

The Economic Commission for Latin America and the Caribbean (Eclac) estimates that the direct cost of replacing the lost and damaged infrastructure in the region after Hurricane Mitch is some Us,000 million (Caballeros, 1999).

Recent large-scale disasters such as Hurricane Mitch and Georges, and the earthquake in Armenia, Colombia have demonstrated the vulnerability of society. It is widely recognized that modern citizen growth, rapid urbanization and the socioeconomic structure in Central America have increased vulnerability of these countries to natural hazards.

These disasters faced by the inhabitants both by natural and anthropological effects lead to the formation of legislation / laws to govern.

Legislation & major acts in U.S. Coastal Zone

The economic loss and economic yield as such felt by the inhabitants of the Earth has resulted in the formation of legislation. This legislation is framed for the sustainable use of the available natural resources. When the loss is severe or the gain is enormous; the laws needs some revision hence they were amended periodically. Some of the Laws and Acts pertaining to U.S. Coastal zone were National Environmental procedure Act, Clean water Act, marine Protection, study and Sanctuaries Act, Ocean Dumping Act of 1972, Water Resources improvement Act of 1996, Coastal Zone management Act of 1972, marine mammal security Act of 1972, Magnuson-Stevens Fishery Conservation and management Act of 1976 Endangered Species Act 1973, Nation wise Invasive Species Act of 1996, Oil Pollution Act of 1990, unabridged environmental response, compensation, and liability act of 1980, Rivers and Harbor Act of 1899, The Submerged Lands Act of 1953, The Fish and Wildlife Coordination Act of 1934, Land and Water Conservation Fund Act of 1965, Outer Continental Shelf Lands Act, reserved supply Conservation and rescue Act of 1976 and The Coastal Barriers Resources Act of 1982.

Hence in order to amend these laws the integration in different fields is attempted and discussed as follows.

Results And Discussion

Assessment of Natural Hazard

Natural hazard is a phenomenon which occurs in proximity and poses a threat to people, structures or economic assets and may cause disaster. They are caused by meteorological, biological, geological, seismic, hydrological, or conditions or processes in the natural environment. Hazard estimate is the process of estimating, for defined areas, the probabilities of the occurrence of potentially - damaging phenomenon of given magnitudes within a specified period of time. Hazard estimate involves determination of formal and informal historical records, and skilled interpretation of existing meteorological, topographical, geological, geomorphologic, hydrological, and land-use maps.

Office of United Nations improvement Relief society (Undro), defines the term vulnerability as: "The degree of loss to a given element or set of elements at risk resulting from the occurrence of a natural phenomenon of a given magnitude. It is expressed on a scale from 0 (no damage) to 1 (total damage)". The vulnerability of an element is regularly expressed as a ration loss (or as a value between 0 and 1) for a given hazard severity level. The portion of loss used depends on the element at risk, and accordingly may be measured as a ratio of the numbers of persons killed or injured to the total population, as a heal cost or as the degree of corporeal damage defined on an acceptable scale. In a large whole of elements, like building stock, it may be defined in terms of the proportion of structure experiencing some singular level of damage.

Assessment is an interdisciplinary process under-taken in phases and piquant on-the-spot surveys and the collation, estimate and interpretation of facts from discrete sources with regard to both direct and indirect losses, short- and long-term effects. It involves determining not only what has happened and what aid might be needed, but also defining objectives and how relevant aid can categorically be in case,granted to the victims. It requires concentration to both short-term needs and long-term implications.

The United States is becoming more vulnerable to natural hazards mostly because of changes in citizen and national wealth density. Due to this, citizen and infrastructure have become concentrated in disaster-prone areas. Natural Hazards threaten the sustainable improvement of United States, destroying years of improvement efforts and investments, placing new demands on society for reconstruction and rehabilitation, and shifting improvement priorities away from long-term goals while immediate needs are met. For most of the 20th century, the United States has largely spared the expense for catastrophic natural disaster. vital improve has been made in insight the discrete impacts that hazards furnish on human and natural environments. Numerous study activities have been undertaken following the major hazard events of the past few years. Unfortunately, much of this study is piecemeal and has not been incorporated into any type of unabridged database on disaster losses.

Natural hazards such as hurricanes and earthquakes do not have to become natural disasters. With allowable planning, along with allowable environment management, much of the risk can be reduced. The risks posed by natural hazards in United States are exacerbated by group and environmental trends such as rapid urbanization and unplanned human settlements, poorly engineered construction, lack of adequate infrastructure, poverty, and inadequate environmental practices such as deforestation and land degradation.

Given the vital costs of the nation's catastrophic natural disasters, focus has shifted in modern years to improve beyond emergency preparedness and response to include a more long-term emphasis on disaster loss reduction. Hence it requires for a quantitative estimate of natural hazards vulnerability for coastal zone. This quantitative estimate of natural hazards is aimed to minimize either an individual's or a community's vulnerability to hereafter disaster damages. Over the years, improve has been made in reducing hazard impacts through good predictions, forecasts, and warnings, particularly for meteorological hazards such as coastal storms and floods. general improvements in hurricane and tsunami prediction, and river and lake level forecasting, have been potential using the most recent in computer modeling technology. Noaa's National Weather assistance (Nws) is currently working with several new technological systems that are intended to significantly enhance hereafter flood forecasting capabilities. Though there were lot of techniques available to assess vulnerability due to natural hazard quantitatively still it is vital to answer the scientific and technological facts needs throughout the discrete hazards-related disciplines and integration. Although vital improve has been made in the study and science related with natural hazards while the past 20 years, and improvements in technology and insight about natural hazards and how to entrance its vulnerability quantitatively requires a real-time networked scientific database.

Universities and study institutions (particularly the National Science Foundation), along with government agencies such as Noaa and Usgs that avow scientific hazards-related responsibilities, have contributed to advances in the scientific study of natural hazards. There is now more quantitative facts available about the origins and behavior of hazard events but the understanding of integration of the available data sets is lagged.

This study is to join all the fields acting in coastal zone for the estimate of vulnerability. Maps delineating hazard-prone areas at national, state, and local levels are needed to provide more unabridged hazards estimate using facts on a collection of natural phenomena, along with coastal storms, floods, tsunamis, hurricanes, typhoons, landslides, wildfires, drought, earthquakes, etc. Much of this facts already exists, but issues such as data integration, compatibility, scales, accuracy, and resolution need to be addressed to make the facts beneficial at the local level. good methodologies and models are also needed for conducting hazard vulnerability assessments that can join highly changeable local conditions and characteristics. This calls for the site specific models for good estimates.

Computer-based geographic facts systems could be used to analyze hazards facts and provide national risk estimate data to state and local governments in quick and easy manner. specific models could be generated by using the Gis software. New high-resolution remote sensing capabilities could be examined for use in large-scale risk and vulnerability assessment. Hence, remote Sensing and Gis is to be intergrated and modeled for the estimate of quantitative natural hazard vulnerability.

Improvements in monitoring, data collection, and data processing inventory for most of the advancements made in short-term weather-related forecasting. good modeling capabilities, along with a more acceptable insight of variables, such as global atmosphere change and sea-level rise, are needed to enhance long-range forecasting and planning for coastal hazard impacts.

Gis integration / modeling for natural hazard vulnerability

Gis is one of the remarkable tools which can be used for the estimate of Natural Hazards Vulnerability (Nhv). Due to these techniques, natural hazard mapping and vulnerability estimate could be performed for the coastal zone. These maps will help the authorities for quick estimate of potential impact of a natural hazard and initiation of acceptable measures for reducing the impact. This data will help the planners and decision-makers to take safe bet steps in time.

Gis applications in the coastal zone are diversified and case-based. Applications studies such as (a) coastal mapping, (b) environmental monitoring, (c) coastal process modelling, (d) pilotage and port facilities management, (e) coastal environmental / hazard assessment, (f) coastal management / strategic planning, and (g) coastal ecological modeling could be done through Gis.

Coastal Mapping is mainly focused on thematic mapping in the coastal zone, such as mapping chlorophyll concentration using Tm data (Chen et al. 1996). Environmental monitoring is one of the routine tasks in Czm, which include monitoring water potential and habitat/biodiversity, and beach watch. Coastal processes modeling of corporeal environment change in the coastal zone includes the simulation of effects of sea-level rise (Ruth and Pieper 1994, Grossman and Eberhardt 1992, Zeng and Cowell 1998, 1999, Hennecke 2000), the estimate of human intervention of coast change (Huang et al. 1999), the use of historical data to predict hereafter coastline change (Sims et al. 1995) and the study of beach morphodynamics (Humphries and Ligdas, 1997). There are other two subcategories of the applications of hazards, namely, short-term and long-term tasks. The old is exemplified with monitoring and predicting oil spill (Belore, 1990), while the latter is demonstrated by coastal hazard / vulnerability estimate due to atmosphere change (Lee et al. 1992, Sims, et al., 1995; Deniels et al. 1996, Hickey et al. 1997, Zeng and Cowell 1999, Hennecke et al. 2000, Esnard et al. 2001). Coastal management / strategic planning involve assessing sustainability of the environment, group and economic viability. The above said studies carried out in coastal zone are to be integrated using remote sensing and Gis for analysis.

The categories of Gis applications in coastal zone could be broadly categorized into three levels.

a) Level 1: as data management and mapping tools,

b) Level 2: as basic data determination (query) and mapping tools, and

c) Level 3: as decision-supporting tools (modelling / simulation).

Most current implementations of Coastal Gis are still at Level 1 and Level 2. It is startling that Level 3 implementations will rapidly growth in the near hereafter as the lasting revision in Gis functions and more user-friendly interface become available in the market. Hence for the study of Quantitative estimate of Natural Hazard Vulnerability Level 3 application is to be adopted.

The two basic arrival / analysis, which should be followed for geospatial database improvement were given below.

Integrated approach:

a) integration of different level of application,

b) integration of vector and raster (data and functions),

c) integration of knowledge of different expertise, and

d) integration of different scales in time and space.

Because of the nature of integration, Gis applications should consider long-term integration. This includes the vertical integration that involves different application (and potential) levels, and horizontal integration that involves other interest groups. Therefore, issues must be addressed from database design, data sharing to tool-making (analysis functions) and caress sharing.

Multi-criteria analysis

a) multi - factors controls

Since coastal principles has a complex hierarchical structure with multi-forcing exerting on each of subsystem, no mater which aspect of the principles to be investigated, multi-variable determination is an vital methods in the coastal environment.

b) multi - discipline arrival for decision Other than the multi-factors, there are many interest groups of coastal community, therefore, good solutions to any coastal issues can only be derived from multidiscipline approach.

Output of the analysis

I. Historical and real-time facts with respect to natural hazards will be gathered by satellite remote sensing, aerial photographs and by other accepted means and integrated with Gis Rdbms. This results in an unabridged geo- database.

Ii. Through the modeling technique and by using the Gis Rdbms we can rate the likelihood of experiencing specific natural hazard in the future, and an estimate of intensity and probable level of impact.

Each natural hazard will be evaluated for three characteristics:

1. Likelihood of Occurrence, i.e., startling frequency;

2. Likely Range of Impact, i.e., predictable size and location of impact; and

3. Probable Level of Impact, i.e., estimated drive and damage potential.

Iii. The level of severity of natural hazards will be quantified in terms of the magnitude of the occurrence as a whole (event parameter) or in terms of the effect the occurrence would have at a singular location (site parameter).

Iv. For quantitative natural hazard vulnerability, some weight value has to be added to the attribute column (slope, subsurface geology, current action, wave action, meterology, wind performance etc). The values that will be given in the attribute columns could be calculated with the help of the equation 1 modeled in Gis environment.

Natural hazard = (Wgeology + Wslope + Wwind + Wmeteo + Wsiesmisivity

+ Wgeomorphology + Wetc...) (1)

Based on the above formula, natural hazard vulnerability values could be retrieved by clicking on any land parcels from the coastal zone map. Such kind of values will have no meanings for the end users. To make the effect more acceptable, a separate domain is to be created in which the resultant values will be divided into three classes: very high, high, moderate and low hazard areas
Weights Class:

Values below than 30 Low hazard Area

Values between 30-40 Moderate Hazard Area

Values between 40-50 High Hazard Area

Values between 50-60 Very High Hazard Area

V. Hazard mitigation plan is to be developed and it will possess these five steps -

o identification of natural hazards that could impact the community,

o assessment of the community's vulnerability to natural hazards,

o assessment of the community's potential to answer to a natural disaster,

o assessment of the community's current policies and ordinances that work on hazard mitigation, and

o development of hazard mitigation strategies that can be implemented to reduce hereafter vulnerability.

Vi. By using all the above factors site specific models for the estimate of natural hazard vulnerability could be generated using Gis for U.S. Coastal zone. This will serve as an input for further amendment of legislation implicated with U.S coastal zone.

Conclusion

U.S. Coastal counties possess economic gain through natural resources, marine trade and industry and economic loss through natural hazards, overexploitation and exponential citizen growth. About 80 percent of the losses were by meteorological events and 10 percent were by earthquakes and volcanoes. Hence in order to minimize the loss due to natural hazard a computer based geospatial database methodology is adopted for natural hazards facts retrieval and to provide national risk estimate data to the state and local governments. Site specific models were proposed for U.S. Coastal zone by integrating Gis software and high-resolution remote sensing to quantify the large-scale risk and vulnerability. This modeling study could also be applied to developing countries such as India, Pakistan, Srilanka etc. For the natural hazard vulnerability estimate in their coastal zones.

Methodology For appraisal Of Natural Hazard Vulnerability In Us Using Remote Sensing

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